From the architect. The Periscope is an office building located in the Upper Circular Road conservation area in Singapore. This area is made up of warehouses and shophouses that serviced the commercial activity around the nearby Singapore River until the latter half of the 20th century. The area has recently undergone regeneration and the restored buildings that now accommodate offices, hotels, restaurants and shops.

Our site comprises a listed 19th century shophouse, which was remodelled in the 1930s. It has road access along the front via a covered public walkway and pedestrian service access along the rear of the building. There are traces of both the 19th century and 1930s interventions and our addition is positioned so that it reads as a distinct layer in addition to more historic ones.

The Singaporean conservation rules allowed us to redevelop the site behind the first 7.5 metres. Our strategy is therefore to retain the original features and character of the front portion of the building as much as possible and create our insertion to the rear of and above it, thereby keeping it as a distinct entity.

The extension comprises a service core with office spaces to its rear which ascends four storeys before cantilevering on the top floor over the historic roofline. The cantilever lies behind this conservation boundary and together with the vertical portion of the extension acts as a visual frame to the listed building.

A two metre deep airwell separates the extension from the existing building. It ensures that light and ventilation is maintained throughout the deep building, a device borrowed from traditional shophouses in this region. Planning rules also dictated that we keep the side walls blank to allow future adjacent development. In the meantime we propose roughcast side walls made of reinforced concrete that act to accommodate the cantilever structurally. The front and rear facades in contrast are made with lightweight perforated aluminium panels to act as sunscreens for these facades.

Location to be used only as a reference. It could indicate city/country but not exact address.Cite:"Periscope / VW+BS" 28 Aug 2011. ArchDaily. Accessed . <http://www.archdaily.com/162071/periscope-vwbs/&gt